Speakman was a member of the
Cronulla branch of the
Young Liberals. During his time in the
United Kingdom, he paid £6 to become a life member of the
Cambridge University Conservative Association. Speakman had challenged Mutch for the Cook preselection prior to the
1998 federal election, but withdrew from the contest when former state deputy Liberal leader,
Bruce Baird, became the compromise candidate. At the
2011 state election, Speakman was elected with a swing of 9.4 points and won the seat with 75.5 per cent of the vote on a
two-party-preferred basis. Speakman's main opponent was Stefanie Jones, representing
Labor.
Premier Barry O'Farrell considered elevating Speakman to the
ministry following the election, but he was not made a minister until April 2015 when, following the
2015 state election, he was appointed as
Minister for the Environment, the
Minister for Heritage, and the
Assistant Minister for Planning in the second Baird ministry.
Gladys Berejiklian was elected as
Liberal leader and sworn in as Premier. The
First Berejiklian ministry was subsequently formed with Speakman sworn in as the Attorney General of NSW with effect from 30 January 2017. a title subsequently amended as the
Minister for the Prevention of Domestic Violence and Sexual Assault in May 2021. In the second arrangement of the Perrottet ministry, he retained the portfolio title of Attorney General. In September 2018, Speakman reportedly broke
Victor Dominello's arm in an office
arm wrestling match. In April 2023, after the Liberal Party’s defeat in the
2023 New South Wales state election, he was elected as Leader of the Liberal Party and hence Leader of the Opposition. On 9 June 2023, Speakman was granted retention of
The Honourable title by the
Governor for life, for having served as a Member of the
Executive Council for more than three years. On 20 November 2025, following rifts in leadership and slipping poll performance, Speakman resigned as leader of the NSW Liberal Party. He endorsed
Kellie Sloane, current
Shadow Health Minister and MP for
Vaucluse, to succeed him. ==Political views==